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3 years ago

A closed rectangular box with a sqaure

Mathematics

1 answer:

deff fn [24]3 years ago

6 0

Answer:

4 inches on each edge of the cube

Step-by-step explanation:

A closed box will have minimum area when it is a cube. For a volume of 64 in^3, the edge length must be ∛64 = 4 inches.

_____

Using derivatives, the base edge length can be defined as x, and the surface area as ...

S = 2x^2 + 4x(64/x^2)

This is minimized when dS/dx = 0:

dS/dx =- 4x -256/x^2 = 0

x^3 = 64

x = ∛64 = 4 . . . . . should look familiar

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wolverine [178]

Step-by-step explanation:

a is the correct not sure though

4 0

3 years ago

Read 2 more answers

Find the value of X.

klemol [59]

Answer:

I think answer is 3

Step-by-step explanation:

BD = DA

BE = EC

Now, BD/BE = DA/EC

or, x + 5/2x = 4/3

or, 3x + 15 = 8x

or, 15 = 8x - 3x

or, 15 = 5x

or, 15/5 = x

or, 3 = x

Therefore x = 3 <u>Ans</u>

5 0

3 years ago

The amount Troy charges to mow a lawn is proportional to the time it takes him to mow the lawn. Troy charges $30 to mow a lawn t

Inessa05 [86]

Answer:

D = 20H

Step-by-step explanation:

The amount Troy (D, in dollars) charges to mow a lawn is proportional to the time (H, in hours) it takes him to mow the lawn.

Hence, we can write D = kH ......... (1), where k is a constant.

Now, given that Troy charges $30 to mow a lawn that took him 1.5 hours to mow.

So, from equation (1) we get

30 = 1.5k

⇒ k = 20.

Therefore, equation (1) becomes D = 20H (Answer)

3 0

3 years ago

1. Marcus can type 40 words in half a minute. Rhys can type 100 words in one and a half minutes. Which student can type at a gre

Bingel [31]

If Marcus can type 40 words in half a minute, then 40 times 2 equals 80. 80 words a minute for Marcus. If Rhys can type 100 words in 1 1/2 minute, 100/ 1.5 = 66.66 and 80>66.66 so Marcus can type a greater rate of words per minute.

5 0

3 years ago

Simplify the expression (2 square root sign 27) - (3 square root sign 32)

monitta

Answer:

$3\sqrt{3} - 4\sqrt{2}$

Step-by-step explanation:

The expression (2 square root sign 27) - (3 square root sign 32) is $2\sqrt{27} - 3\sqrt{32}$ .

To simplify, simplify inside the radicals by removing perfect square factors.

$\sqrt{27} =\sqrt{9*3} =3\sqrt{3}$

$\sqrt{32} =\sqrt{16*2} =4\sqrt{2}$

The expression becomes $3\sqrt{3} - 4\sqrt{2}$ .

This cannot be simplified anymore because whats under the radical is not the same.

6 0

3 years ago